Previous studies have detected locations of electrode tips in cortices by combining anatomical information acquired with MRI and tip positional information acquired by other techniques such as radiography (Nahm et al, Exp. Brain Res., 1994) or sonography (Glimcher et al, J. Neurosci. Methods, 2001). In this study, we tested the detectability of electrode tips directly on anatomical MR images. We first conducted in vitro study to optimize MR scan conditions and examined the accuracy of the tip detection. As a phantom we used a glass insulated tungsten electrode and reference glass tubes that were sunk together in Copper Sulfate solution. To estimate the accuracy of tip detection, distances between the electrode and the reference glass tubes were measured and compared in two different ways; one using MRI and the other using an optical microscope. MR images were acquired with a 4.7 T MRI scanner (Biospec 47/40, Bruker, Ettlingen) using a Fast Spin Echo sequence (in-plane resolution=50-200 µm by side, TR=1000-...

Introduction: Deception is a psychological process by which one individual deliberately attempts to convince another to accept as true what the first individual knows to be false. To deceive other person requires inhibition of true response and producti...

Major Depressive Disorder (MDD) is a mood disorder with a lifetime prevalence of approximately 20% in the US [1]. MDD is characterized by persistent feelings of sadness and apathy not attributable to any apparent external causes [1]. Fronto-limbic circu...

Previous studies suggest that high resolution MRI can detect amyloid deposits [Benveniste H, 1999]. In this study we used a 11.7T imaging system to record 3-D T2*-weighted gradient echo images at 11.7 µm per voxel of formalin-fixed T1 temporal horn specimens from 3 aged non demented subjects and 3 Alzheimer's disease subjects. Tissue encompassed cerebral cortex and white matter. The samples were then stained for amyloid (Aß) deposits and for iron deposits. In both Alzheimer diseased and control cerebral cortices, hypo-intense spots and halo-like structures were clearly visible in MR images. 3D visualization of the images and comparison of MR images with neuropathology revealed that some of the hypo-intense structures were blood vessels. Due to susceptibility effects caused by residual iron, the blood vessels appeared larger in MR images than in neuropathological slices. In some Alzheimer samples, spots in the MR images had a geographical pattern similar to the pattern of amyloid deposits. However, in other...

It is now well established behaviorally that syncopation (moving antiphase to a pacing stimulus) is intrinsically less stable and requires more attention than inphase synchronization. Recent fMRI results have shown that, relative to synchronization, syncopation results in significant increases in activation of cortical and subcortical areas involved in planning, preparation and timing. We investigated the degree to which this increased activation is altered by practice. Baseline levels of the BOLD response were obtained from eight subjects while they syncopated or synchronized with an auditory metronome at 1.25 Hz. Subjects then practiced syncopation at the same rate while fMR images were acquired continuously. Post practice scans of the two coordination modes were then performed. Before practice, baseline syncopation was associated with significantly greater activation than synchronization in SMA, pre-motor cortices and cerebellum, reflecting the extra planning and timing requirements of syncopation. Acti...

In our hypoxia-ischemia induced cerebral palsy animal model, acute changes in apparent diffusion coefficient (ADC) in fetal brain during uterine ischemia predicts which fetuses will become hypertonic. There is a ‘normal’ ADC threshold and only fetuses w...

Experience-driven changes of sensory inputs cause reorganization of cortical sensory maps in the adult brain. Our lab postulated that down-regulation of Nogo receptor (NgR) is one prerequisite for structural reorganization of synaptic circuitry. However...

Locomotion or passive foot motion increases respiratory rate and tidal volume, a relationship of interest as a means to stimulate breathing for patients with sleep-disordered breathing, especially children with hypoventilation disorders. To determine th...

Background and purpose- In humans, it has been demonstrated that neural substrates for tactile shape discrimination display a right-sided asymmetry. Right handed tactile object recognition has also been shown to result in predominantly right-sided neura...

Non-Hispanic Black (NHB) individuals report higher rates of discrimination compared to their non-Hispanic White (NHW) counterparts. Further, NHB males report the highest rates of discrimination. Exposure to discrimination that is perceived as stressful ...